This invention relates to a unique chassis arrangement for a land vehicle. More specifically, to a unique chassis arrangement and equipment arrangement for a ground fed blender truck for use in well fracturing operations.
One common way to increase the production of a well, such as an oil, gas, geothermal, etc. type well, is to fracture the producing zone of the geological formation to allow the formation fluids to flow more freely through the formation into the well. The producing zones of geological formations are usually fractured by pumping fluids into the formation under high pressures. However, if merely a fluid is pumped into the formation during the fracturing operation, upon cessation of the pumping of the fracturing fluid, the naturally occurring geological formation pressures will cause the fractured areas of the formation to close thereby restricing the flow of the formation fluids.
To prevent the geological formation from closing after the fracturing thereof, propping agents, such as sand, walnut shells, glass beads, sintered metals, etc., are forced into the fissures in the formation. Accordingly, the function of a blender truck is to accurately mix the particulate propping agents and additive materials with the fracturing fluid before the injection of the fracturing fluid into the well.
In the past, one type of blender truck has been constructed having the blender tub rigidly mounted on the rear of the truck chassis, having the particulate propping agents supplied to the blender tub by screw type conveyors, having the mixed fracturing fluid removed from the blender tub by a centrifugal or gear pump and having the major components of the blender truck directly driven by the truck engine while the other components of the blender truck are driven hydraulically. A disadvantage results from having all the components being operated by the truck engine in that if it is necessary to slow the blender tub mixing speed, a corresponding drop in hydrualic system pressure and the reaction time of the hydraulic system components occurs thereby making it difficult to accurately control the additive mixing rates in the fracturing fluid. Yet another disadvantage results in the maintenance and repair of the pumps and their associated components due to the inaccessibility of their mounting position and the high frequency of repair of the screw type conveyors due to the erosion thereof by the abrasive materials conveyed thereby.
Typical examples of these prior art blender trucks are shown on page 128 of the Halliburton Services Sales and Service Catalog 1970-71, and page 2942 of the Halliburton Services Sales and Service Catalog Number 38.